Self-closing mechanism

ABSTRACT

Automatic self-close mechanism, in particular for closing a toilet bowl seat and/or a toilet bowl lid, where said closing of the seat and/or lid may be separated into two movements, a first movement bringing the seat and/or lid from a position resting against a back stop into a position where gravity will propel the seat and/or Hd downwards, and a second movement where gravity propels the seat and/or lid towards the toilet bowl, where the energy necessary for the first movement is stored in a resilient member during the opening of the seat/lid, and that the energy is released by releasing a locking arrangement, where said locking arrangement is actuated by an actuating wire, said wire pulling the locking arrangement out of locking engagement, where said wire is actuated by electrical means.

FIELD OF THE INVENTION

The present invention relates to an automatic self-closing mechanism, a method for controlling the closing of a toilet bowl seat and lid and a locking mechanism for use in a self-closing mechanism, particularly for a closing mechanism used for closing the toilet seat and/or lid in a toilet construction.

Toilet seat lid and seat raising and lowering devices of various designs and configurations are well-known in the prior art. Numerous such devices have been constructed and used for the purpose of lowering toilet seats and lids; and, in some cases for also raising toilet seats and lids. The prior art includes for example:

U.S. Pat. No. 5,388,281 issued to Wiklund, et. al., discloses a toilet seat having a mechanism for automatically lowering the seat after a time interval in the raised position. This mechanism has a hydraulic section and a dry-spring section contained within a hollow rotor which is constructed as part of the rear of the toilet seat. The time interval is the result of fluid escaping from the hydraulic mechanism (referred to as the dashpot). The coil spring provides the energy to urge the seat downward after the time interval has passed. Fluid pressure and valves dampen the closing so that the seat descends slowly to the closed position. This mechanism is constructed such that it can be adapted to existing toilet seats to provide an unobtrusive closing mechanism to existing fixtures.

U.S. Pat. No. 5,546,612 issued to Johnson discloses an automatic toilet seat lowering device integrated into a seat hinge assembly. Initial lowering action results after a coiled spring is released causing the seat to free fall for a partial distance. Descent is controlled thereafter by a friction caused between a combination of rotating and non-rotating brake discs mounted within the device. Interaction between these brake discs, the compression of a disc spring, and a reverse resistance on a torsion spring within the device serve to slow the initial free fall of the seat into a controlled soft landing to the seat's resting place.

Other patents include U.S. Pat. No. 4,551,866 to Hibbs (utilizing an operating cylinder and a piston); U.S. Pat. No. 4,912,783 to Shafer (utilizing a torsional coil spring, dampening cylinders, and a circumferential groove for engagement with a spring biased locking pin); U.S. Pat. No. 4,995,120 to Tager (utilizing an electric motor, a ratchet clutch mechanism, and a timer); U.S. Pat. No. 5,349,703 issued to Mocilnikar, et. al. (utilizing a toothed sprocket which engages a rotatable sleeve having corresponding teeth); U.S. Pat. No. 5,487,192 issued to Hodges (utilizing a manually operated control lever for raising and lowering a toilet seat); and U.S. Pat. No. 5,504,947 issued to Robello, et. al. (utilizing an air controlled cylinder secured to a toilet bowl and seat).

From WO 2006/053560 is the applicants own earlier construction known addressing the problem of automatically releasing and lowering the seat and/or lid after a user has left. The mechanism operates by storing energy in a torsion spring while the lid and/or seat are being opened. As the hinge construction is lowered due to a load placed on the seat and/or lid, two pins will engage a locking mechanism, thereby avoiding the force in the torsion spring being released. As the load is removed the pins are released from their engagement, and a dampener will delay the release of the torsion springs energy. As this energy is released the seat and/or lid will move towards the closed position, during which the dampener controls the speed of the movement.

Each of these prior art patents have attempted to solve a long-felt problem; automating the lowering of a toilet seat and lid whether singly or in combination in a most efficient, effective, and inexpensive means with the least amount of moving parts while preserving the aesthetics of the surroundings to the extent practicable. None of the prior art patents has accomplished each of these objects and objectives.

OBJECT OF THE INVENTION

It is an object of the present invention to provide an automatic self-close mechanism which in addition to providing a highly reliable self-close mechanism also provides a locking arrangement such that the toilet seat and/or toilet lid will securely remain in the open position due to the activation of a locking arrangement.

DESCRIPTION OF THE INVENTION

The present invention addresses this by providing an automatic self-close mechanism, in particular for closing a toilet bowl seat and/or a toilet bowl lid, where said closing of the seat and/or lid may be separated into two movements, a first movement bringing the seat and/or lid from a position resting against a back stop into a position where gravity will propel the seat and/or lid downwards, and a second movement where gravity propels the seat and/or lid towards the toilet bowl, where the energy necessary for the first movement is stored in a resilient member during the opening of the seat/lid, and where the energy is released by releasing a locking arrangement, where said locking arrangement is actuated by an actuating wire, said wire pulling the locking arrangement out of locking engagement, where said wire is actuated by electrical means.

The provision of an actuating wire being activated by electrical means in combination with a locking arrangement ensures that no unwanted closing of the seat or lid occurs. Furthermore, in this manner it is possible to provide a very effective locking arrangement in that prior art arrangements all relied on some kind of mechanical or biasing member slowly releasing its force after which it was possible to lower the seat and/or lid. With the present invention, however, it is possible to maintain the open seat and lid in an open position until the electrical means are activated, whereby the wire will release the locking arrangement.

In a further advantageous embodiment the actuating wire is a shaped memory alloy, where the electrical source activates the wire, causing the wire to contract, thereby pulling the locking arrangement out of locking engagement.

In this particular configuration the material characteristics of a shaped memory alloy are used in order to provide the force necessary to disengage the locking arrangement which, due to the characteristics of shaped memory alloys will be a pulling action in that the shape memory alloy will contract when a current is guided through the shape memory alloy. The pulling action thereby releases the locking arrangement out of locking engagement, whereby the energy stored in the resilient member is released so that the lid and/or seat is commencing on a first movement. Once the first movement has been completed, gravity will propel the seat and/or lid further downwards into the closed position.

In a further advantageous embodiment an electronic circuitry is arranged on a printed circuit board, and means for fastening the wire to the circuit board in electrical contact with the source of energy is provided, and futhermore the wire is arranged around a pulley in the locking arrangement and back to the printed circuit board, such that the length of the wire is substantially twice or more of the length between the wire fastening point on the printed circuit board and the locking arrangement.

In this configuration a number of advantages are achieved in that in order to save space and thereby better be able to accommodate the mechanism inside the relatively narrow space provided in a mechanism of this type, the circuit board is used as a fastening point for the wire and at the same time the size of the circuit board is used in order to provide a wire of a certain length.

The pulley provided in the locking arrangement allows the wire to influence the locking arrangement in a linear movement along or parallel to the axis of rotation, i.e. along the axis around which the seat and lid turns in order to go from the open to the closed position and vice versa.

Particularly in the embodiment where the wire is a shaped memory alloy the provision of a wire having a length being substantially twice the distance between the fastening point and the engagement point with the locking mechanism, provides the possibility of first of all increased dimensional change of the wire in that e.g. a Flexinol wire provided by Dynalloy Inc. when heated due to the electrical current lead through the wire will change dimension corresponding to approximately 3% of the entire length. The further advantage is that the wire having to be relatively thin in order to attain the flexibility for these types of application will be able to handle a force in the case where the wire is double, which is twice the force of a single wire. For example for a Flexinol wire of 0.006 inches the force which the wire may be exposed to is approx. 660 gr. This force is sufficient in order to allow the locking arrangement to be released so that the lid and/or seat may proceed through the first movement.

A further advantage of having the wire arranged around the pulley in the locking arrangement is the fact that it is possible to fasten the wire by similar means in the printed circuit board, whereas if the wire had been single, fastening means in the circuit board as well as fastening means in the locking arrangement had to be provided. This could cause a more complicated assembly of the mechanism of the invention.

In a further embodiment of the invention the mechanism comprises a housing where said housing comprises means for attaching the housing to a toilet bowl, and where further a first damper is arranged inside said housing for dampening the movement of the toilet seat, and a second damper also arranged inside the housing is provided for dampening the movement of the toilet bowl lid, where engagement means are provided in either end of the housing for attaching said toilet bowl seat and lid to said dampeners, and where the releasable locking arrangement is provided between the second dampener and the toilet bowl lid.

The housing will typically be the visible part of the invention and hide all the electrical and mechanical parts making up the mechanism. The housing may typically be a tubular member, on the outside of which fastening means are provided so that the housing may be fastened to a toilet bowl. Typically, the housing is fastened by means of bolts going through the material of the toilet bowl so that a firm engagement between the toilet bowl and the mechanism is provided. In either end of the housing attachment means are provided such that the toilet seat and lid may be attached to the mechanism in such a way that the movement of the toilet seat and lid is determined by these engagement means' ability to move. There is therefore a non-rotational connection between the engagement means provided in the mechanism and the corresponding engagement means on the toilet seat and lid. The connection and engagement means will, however, allow the seat and lid to be raised manually from the closed position to the open position.

In order to further provide a smooth closing of the seat and lid, dampeners are provided, so that the toilet seat and lid's second movement will be dampened, whereby a slamming of the seat and lid is avoided. Typically, hydraulic dampeners may be provided for these purposes. A number of dampeners are commercially available and a skilled person would select an appropriate dampener in order to achieve the desired controlled closing of the lid and seat during the second movement.

In a further advantageous embodiment a time delay circuit is included in the electronic circuitry, whereby a predefined time may pass between activation of the locking arrangement and release of said locking arrangement.

By providing a time delay before the closing mechanism is activated, it becomes possible to predefine the time which it is desirable to have the seat and lid in its open position. The time delay circuit may e.g. be activated once the lid and/or seat is in its open position so that after a predetermined number of minutes an automatic self-close of the seat and lid will commence. In this connection it will naturally be understood that the time delay should be of such a length that a user may complete his or her business without being surprised by the seat and/or lid accidentally closing.

In a further advantageous embodiment a proximity sensor is provided, which sensor may detect the presence of a user in the vicinity of the mechanism, and where said sensor is connected to the circuitry in such a manner that the activation of the time delay, causing the locking arrangement to release, is activated by input from said sensor. The proximity sensor is coupled to the time delay circuit in such a manner that instead of using a predetermined fixed time between the moment when the seat and or led is raised and the activation of the self-closing mechanism the sensor will be able to detect when a user is no longer in the vicinity of the self-closing mechanism after which the predetermined time delay commences. In this manner it is assured that a user will be able to use the necessary time in the vicinity of the self-closing mechanism without the lid and/or seat commencing its closing movements. The length of the time delay in this instance may naturally be shorter or there may be a time delay of 0 seconds in that the closing movements may commence directly after a user has left the area in which the sensor is able to detect a user.

The proximity sensor in combination with the time delay circuit, make it possible to pre-design various closing/activation routines. For example it may be contemplated that in situations when the seat and lid are raised but the proximity sensor fails to detect anything inside its detection zone, the delay circuit will not activate the closing routines until a certain period of time has lapsed. The sensors detection zone will typically be set to from 10 cm to 80 cm from the sensor, and in an angle of +/−30. This facility may be desirable when for example cleaning is carried out, or the toilet is used as a trash can, for example in connection with hair brushing, trimming and the like.

The invention is also directed to a method for controlling the closing of the toilet bowl's seat and lid where the seat and lid are engaged in a closing mechanism, where said mechanism comprises a first dampener which dampener is engaged with the seat such that the dampener will slow down the closing movement of the seat, and a second dampener engaged with the lid such that the second dampener will slow down the movement of the lid, and where the opening of the lid will increase the torsional force in a torsion member, and furthermore that a releasable locking mechanism is provided which locking mechanism will, until released maintain the lid in its open position, and after release transfer the stored energy in the torsion member to the lid for moving the lid towards its closed position in contact with the seat,

The method in a further advantageous embodiment is arranged so that the locking mechanism has access to a source of electrical energy whereby the release of the locking mechanism is achieved by electrically heating a shaped memory alloy wire, which thereby contracts and pulls the locking mechanism out of locking engagement, and further optionally that a time delay circuitry is provided, such that the locking mechanism will release and allow the torsion member to initiate the closing of the lid after a predetermined time period.

By providing the source of electrical energy, e.g. in the shape of a battery, it becomes possible to heat a shaped memory alloy wire which by contraction will cause the movement necessary in order to disengage the locking mechanism so that the toilet lid and seat may close. The torsional force stored in a torsional member such as e.g. a helical spring, is generated as described above by the manual opening of the lid and seat. The locking mechanism therefore needs to have a locking power sufficiently large in order to overcome the torsional force stored in e.g. the helical spring arranged inside the mechanism. Once the wire is heated and thereby contracts, the locking mechanism will disengage and thereby release the energy stored in the torsional member such that the movement of the seat and lid will commence as already described above. This mechanism thereby assures a very safe and stable mechanism which is able to avoid accidental closing of the seat and lid by a relatively simple and reliable mechanism.

The invention is furthermore directed to a locking mechanism for use in a self-close mechanism according to any preceding claims, wherein said mechanism is particular in that:

-   -   means for mounting a toilet seat and/or lid are provided, where         said means are arranged in a substantially tubular member,         defining an axis of rotation for the seat and/or lid;     -   the means for mounting the toilet seat and/or lid are arranged         separately such that means in one end of the tubular member by         means of a torsional connection with a first dampener is         provided for dampening the movement of the seat, and that means         in the opposite end of said tubular member by means of a         torsional connection with a second dampener is provided for         dampening the movement of the lid;     -   the means in one end comprises a locking mechanism, where said         locking mechanism comprises a hollow cylindrical section, where         said cylindrical section is integral with the means for mounting         the seat or lid;     -   inside the cylindrical section a piston having a cone shaped         section is moveably arranged such that the piston may move along         the axis of rotation;     -   one or more balls are arranged in one or more slits in the         cylindrical section, such that the balls may move radially         relative to the axis of rotation in or out of engagement with         the tubular member, depending on the position of the piston,         optionally locking recesses may be provided on the inner surface         of the tubular member corresponding to the balls;     -   the piston is moved by activating a shaped memory alloy pulling         the piston in one direction and a resilient member biasing the         piston in the opposite direction along the axis of rotation.

The combination of balls engaging a cone-shaped member which cone-shaped member is a piston movable by means of the shaped memory alloy provides for a mechanical locking mechanism that is extremely reliable. By moving the piston in one direction the balls will be urged outwards and thereby forced into engagement with the rotatable cylindrical section and thereby prevent this section from rotating so that an effective lock is provided. By moving the cone-shaped piston in the opposite direction the balls will be provided with a free space so that the engagement between the balls and the rotatable cylindrical section will be released so that a closing action may commence. Once the piston is in the position where the balls are in firm engagement with the rotatable cylinder and thereby preventing the cylinder from rotating in relation to the rest of the construction a very stable lock is in place preventing the lid and seat from rotating and thereby from closing. As no torsional forces are involved in order to maintain this relationship a very rigid construction is achieved simply by urging the piston to move in one direction so that the balls due to the cone-shaped section on the piston will be urged into engagement with the rotatable cylindrical section. This engagement is maintained as long as the piston is in the position where it urges the balls into locking engagement with the rotatable cylindrical section. By releasing, i.e. allowing the wire to relax whereby the piston will be able to move, the balls will be provided with more space so that they will disengage from the cylindrical section and thereby unlocking and allowing the cylindrical section to rotate in relation to the locking mechanism.

In a further advantageous embodiment the shaped memory alloy is in the shape of a wire and the wire is mounted fastened to an interior part of the cylindrical section in one end, threaded around a pulley arranged in the piston and the other end of said wire being mounted to an interior part of the cylindrical section adjacent the mounting of the first end. The double wire construction provides the advantages which have already been explained above and by doubling the force which the wire may be exposed to without breaking the conical section of the piston may be exposed to quite large loads. In practice, the loads on the wire are largest when the piston is being moved from the unlock position to the lock position; i.e. where the balls are out of engagement with the rotatable cylindrical section, and due to the movement of the conical part of the piston the balls are urged into engagement with the rotatable cylindrical section the forces are largest in that the resistance by the balls on the conical surface of the piston will be the largest. Once the piston has reached its end position, that is to say the position where the balls are urged into locking engagement with the rotatable cylindrical section, the load on the wire diminishes in that the piston shall only be maintained in this particular position and no dynamic forces are being transferred to the wire.

These features are further elaborated in a further advantageous embodiment wherein the wire is mounted to flanges on a circuit board, where said board further comprises a source of energy and a proximity sensor, where an aperture through the tubular member and said cylindrical section allows the proximity sensor to sense if a user is present in the proximity of the locking mechanism, and that the circuitry on the board comprises a time delay circuit, such that a predetermined delay time may be programmed into the circuitry whereby input from the sensor, after the predetermined period, will activate the self-close mechanism, by inducing a current I the wire which thereby contracts and retracts the cone shaped part of the piston, allowing the balls to disengage from the cylindrical section, allowing the cylindrical section to rotate, and thereby close the seat and lid.

DESCRIPTION OF THE DRAWING

FIG. 1 illustrates a cross-section through an embodiment of the invention.

FIGS. 2 and 3 illustrate details relating to the locking mechanism.

FIG. 4 illustrates an embodiment of the invention with a proximity sensor.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 is illustrated a mechanism according to the invention. The mechanism 1 is provided with engagement means 2,3 in each end of the tubular member 4. The engagement means 2,3 are suitable for detachably connecting a toilet seat and/or lid construction (not illustrated). Typically, the connections 2,3 will engage the lid and seat in a non-rotatable manner so that only when the engagement means 2,3 are rotated will the seat and/or lid be able to move from an open position to a closed position. The opening of the lid and seat is not blocked by any features of the invention, but during the opening mechanical energy is stored in a helical spring 5 arranged inside the mechanism 1. The energy is transferred to the helical spring by the connection means 3, and as the seat (not illustrated) is opened, a rotation will occur in the engagement means 3, whereby the helical spring 5 will store an amount of torsional energy. As the movement of the seat reaches its top position, the locking mechanism will engage and block further movement until the locking mechanism 6 has been released. The locking mechanism will be explained in more detail below. Engagement of the locking mechanism will occur due to the fact that the balls 8 are urged radially outwards due to the piston's 9 movement to the right in FIG. 1, urged by the spring 10. The balls may move in that the rotation of the seat and/or lid also rotates the member 11 so that a recess in the member 11, see FIG. 2, is able to accommodate the ball 8 and thereby lock and prevent further movement.

During the closing of the seat and lid the movement may be split into two separate movements. A first movement moving the seat and lid from a rest position into a position where gravity will be able to propel the seat and lid into closing engagement with the toilet bowl. The first movement is powered by the torsional energy stored in the helical spring 5 so that once the locking mechanism 6 releases and allows for rotation, the energy stored in the helical spring 5 is also released and will propel the seat and lid from their rest position into a position where gravity will force the seat and lid down-wards towards their closed position.

In order to avoid that a sudden movement of the seat and lid occurs, dampeners 12,13 are provided so that the dampener 12 will dampen the engagement means' 3 ability to rotate and thereby provide for at control and relatively slow closure of the seat. The same is true for the dampening means 13 which will due to the connection members' 2 cylindrical sections 2′ be dampened by the dampener 13.

The locking mechanism 6 is activated by a shaped memory alloy wire 14 where the ends of the wire 14 is fastened approximately in the same position at fastening points 15,16. The fastening points 15,16 also serve as electrical connectors so that the energy necessary in order to make the shaped memory alloy wire change dimensions is supplied via these connectors 15,16. In this example the connectors 15,16 are arranged on a printed circuit board 17.

In the position indicated in FIG. 1 the balls 8 are out of engagement with the members 11 so that the engagement means 2,3 are free to rotate, i.e. the seat and lid may be opened. When they are rotated to a position as indicated with reference to FIG. 2, the balls 8 may be accommodated in recesses 20, see FIG. 2, arranged in the member 11. The spring 10 will in this position urge the piston 9 forward whereby the flange 18 on the piston 9 will prevent the ball 8 from disengagement of the member 11.

Turning to FIG. 2 the outer member 4 has been removed for illustrative purposes only. The flange 18 is maintaining the ball 8 in connection with the recess 20 of the member 11, so that rotation of the engagement member 2 is prevented.

In FIG. 3 is illustrated a detailed view of the locking mechanism according to the invention. The wire 14 is attached to the piston 9 so that as the wire 14 contracts due to the material characteristics of a shaped memory alloy, the spring member 10 will be compressed. The compression will thereby urge the piston 9 to the right as depicted in FIG. 3. The piston is equipped with a cylindrical section 19 which is dimensioned so that the balls 8 (typically there will be two or more balls) may be accommodated as indicated in FIG. 3 without engaging the member 11. The member 11 is therefore in the illustrated embodiment free to rotate relative to the engagement means 2. In the member 11 is provided recesses 20 as indicated above with reference to FIG. 2 so that the ball may be able to move radially, whereby the tension force in the spring member 10 will urge the piston to the right in FIG. 3, and by the cone-shaped section 21 force the ball through the opening 22 in the engagement means 2 so that the ball will enter the recesses 20 provided in the member 11. This will happened when the shaped memory alloy is deactivated, i.e. when the current is shut off, and the wire regains it original length. During this process the piston 9 will move to the right so that as the ball has been forced into the recess 20 the flange 18 will maintain the ball in this position. The locking mechanism may only be disengaged, i.e. the lock released by allowing the piston to move to the left, i.e. so that the ball by means of the cone-shaped section 21 of the piston 9 is allowed to move radially into the position where it rests on the cylindrical surface 19 of the piston 9 and thereby releases the member 11 which may thereafter freely rotate. The movement of the piston is achieved by providing an electrical current in the shaped memory alloy 14 which thereby contracts and compresses the spring 10 at the same time.

As an alternative to a shaped memory alloy the locking mechanism could also be activated by a regular steel wire being wound around an electrical motor so that the contraction occurs as the motor is rotated in one direction and the release of the engagement section 2 occurs when the electrical motor is either decoupled or brought to rotate in the opposite direction so that the spring member 10 will release its force and urge the piston 9 into the position as illustrated with reference to FIG. 2.

Turning to FIG. 4 the same construction is illustrated with the addition of a proximity sensor 23. As the outer member 4 rotates due to the opening of the seat and lid, an aperture will be superposed the centre so that the sensor will be able to detect whether a user is in the vicinity of the device. In this embodiment the sensor is a light detecting sensor, but any type of sensor may be used within the context of the present invention. The sensor may be coupled to en electrical circuitry placed on the printed circuit board 17 so that a pre-programmed time delay may be activated once the sensor detects that a user is not in the vicinity of the device so that the closing action as described above may commence.

Above the invention has been described with reference to a construction comprising both a toilet seat and a toilet lid (or cover). It should however be understood that the principles of the invention also are applicable to seats or lids alone.

The invention has now been described with respect to one particular embodiment, but the scope of protection shall only be limited to what is defined in the appended claims. 

1. An automatic self-close mechanism, in particular for closing a toilet bowl seat and/or a toilet bowl lid, where said closing of the seat and/or lid is separated into two movements, a first movement bringing the seat and/or lid from a position resting against a back stop into a position where gravity will propel the seat and/or lid downwards, and a second movement where gravity propels the seat and/or lid towards the toilet bowl, where the energy necessary for the first movement is stored in a resilient member during the opening of the seat/lid, and that the energy is released by releasing a locking arrangement, where said locking arrangement is actuated by an actuating wire, wherein the actuating wire is a shaped memory alloy, and that an electrical source activates the wire, causing the wire to contract, thereby pulling the locking arrangement out of locking engagement, where said wire is actuated by electrical means.
 2. (canceled)
 3. The mechanism according to claim 1 wherein an electronic circuitry is arranged on a printed circuit board, and that means for fastening the wire to the circuit board in electrical contact with the source of energy is provided, and furthermore that the wire is arranged around a pulley in the locking arrangement and back to the printed circuit board, such that the length of the wire is substantially twice or more of the length between the wire fastening point on the printed circuit board and the locking arrangement.
 4. The mechanism according to claim 1 further comprising a housing, where said housing comprises means for attaching the housing to a toilet bowl, and that further a first damper is arranged inside said housing for dampening the movement of the toilet seat, and a second damper also arranged inside the housing is provided for dampening the movement of the toilet bowl lid, where engagement means are provided in either end of the housing for attaching said toilet bowl seat and lid to said dampeners, and that the releasable locking arrangement is provided between the second dampener and the toilet bowl lid.
 5. The mechanism according to claim 1 wherein a time delay circuit is included in the electronic circuitry, whereby a predefined time may pass between activation of the locking arrangement and release of said locking arrangement.
 6. The mechanism according to claim 5 wherein a proximity sensor is provided, which sensor may detect the presence of a user in the vicinity of the mechanism, and where said sensor is connected to the circuitry in such a manner that the activation of the time delay, causing the locking arrangement to release, is activated by input from said sensor.
 7. A method for controlling the closing of a toilet bowl seat an lid, where the seat and lid are engaged in a closing mechanism, where said mechanism comprises a first dampener which dampener is engaged with the seat such that the dampener will slow down the closing movement of the seat, and a second dampener engaged with the lid such that the second dampener will slow down the movement of the lid, and where the opening of the lid will increase the torsional force in a torsion member, and furthermore that a releasable locking mechanism is provided which locking mechanism will, until released maintain the lid in its open position, and after release transfer the stored energy in the torsion member to the lid for moving the lid towards its closed position in contact with the seat, where the locking mechanism has access to a source of electrical energy, such that the release of the locking mechanism is achieved by electrically heating a shaped memory alloy wire, which thereby contracts and pulls the locking mechanism out of locking engagement.
 8. The method according to claim 7 wherein a time delay circuitry is provided, such that the locking mechanism will release and allow the torsion member to initiate the closing of the lid after a predetermined time period.
 9. The method according to claim 7 wherein the locking mechanism has access to a source of electrical energy, and that a sensor is provided, whereby the sensor may detect the presence of a user in the vicinity, and only release the locking mechanism after a user has left the vicinity or after a predetermined time period has lapsed after a user has left the vicinity.
 10. A locking mechanism for use in a self-close mechanism according to any preceding claims, wherein said mechanism is particular in that: means for mounting a toilet seat and/or lid are provided, where said means are arranged in a substantially tubular member, defining an axis of rotation for the seat and/or lid; the means for mounting the toilet seat and/or lid are arranged separately such that means in one end of the tubular member by means of a torsional connection with a first dampener is provided for dampening the movement of the seat, and that means in the opposite end of said tubular member by means of a torsional connection with a second dampener is provided for dampening the movement of the lid; the means in one end comprises a locking mechanism, where said locking mechanism comprises a hollow cylindrical section, where said cylindrical section is integral with the means for mounting the seat or lid; inside the cylindrical section a piston having a cone shaped section is moveably arranged such that the piston may move along the axis of rotation; one or more balls are arranged in one or more slits in the cylindrical section, such that the balls may move radially relative to the axis of rotation in or out of engagement with the tubular member, depending on the position of the piston, optionally locking recesses may be provided on the inner surface of the tubular member corresponding to the balls; the piston is moved by activating a shaped memory alloy pulling the piston in one direction and a resilient member biasing the piston in the opposite direction along the axis of rotation.
 11. The locking mechanism according to claim 10 wherein the shaped memory alloy is in the shape of a wire, and that the wire is mounted fastened to an interior part of the cylindrical section in one end, threaded around a pulley arranged in the piston and the other end of said wire being mounted to an interior part of the cylindrical section adjacent the mounting of the first end.
 12. The locking mechanism according to claim 9 wherein the wire is mounted to flanges on a circuit board, where said board further comprises a source of energy and a proximity sensor, where an aperture through the tubular member and said cylindrical section allows the proximity sensor to sense if a user is present in the proximity of the locking mechanism, and that the circuitry on the board comprises a time delay circuit, such that a predetermined delay time may be programmed into the circuitry whereby input from the sensor, after the predetermined period, will activate the self-close mechanism, by inducing a current I the wire which thereby contracts and retracts the cone shaped part of the piston, allowing the balls to disengage from the cylindrical section, allowing the cylindrical section to rotate, and thereby close the seat and lid. 